$(12-9i)+(32-6i)=$ Express your answer in the form $(a+bi)$.
Answer: Background Complex numbers can be added or subtracted by separately adding or subtracting their real and imaginary terms. To add or subtract complex numbers: Expand parentheses (attending to minus signs outside of parentheses if necessary) Combine all real terms (terms that do not contain $i$ ), and add or subtract them. Combine all imaginary terms (terms that contain $i$ ), and add or subtract them. Combining Like Terms $\begin{aligned} ({12}{-9}i)+({32}{-6}i)&={12}{-9}i+{32}{-6}i \\\\ &={12}+{32}{-9}i{-6}i \\\\ &={44}{-15}i \end{aligned}$ Summary $({12}{-9}i)+({32}{-6}i)={44}{-15}i$